function startCourse()

{

        // check to see if cookies is enabled, otherwise, this won't work
          if( typeof sessionStorage == "undefined" || sessionStorage.disabled )

        {
           alert( "You must enable cookies for this course to work properly." );

        }

        else

        {
           // if it is enabled, checked to see if this course was started
          // if it was not able to retrieve, the key "course_started", then
          // then this is the first time we are running the course
           if( !sessionStorage.getItem( "course_started" ) )

	        {

	                // clear the session storage
                   sessionStorage.clear();
                // set the "key" by giving it a value.  all values are strings!
                sessionStorage.setItem( "course_started", "1" );
                sessionStorage.setItem( "Ceres", "0")
                sessionStorage.setItem( "Pallas", "0" );
                sessionStorage.setItem( "Juno", "0" );
                sessionStorage.setItem( "Vesta", "0" );

	                

	        }

        }

}

function visitVesta()
{

        sessionStorage.setItem( "Vesta", "visited" );

        showQuiz();
} 

function visitJuno()
{

        sessionStorage.setItem( "Juno", "visited" );

        showQuiz();

}



function visitPallas()

{

        sessionStorage.setItem( "Pallas", "visited" );

        showQuiz();

}


function visitCeres()

{
	sessionStorage.setItem( "Ceres", "visited" );

        showQuiz();

}


// this function will check to see if every page was visited

// if so, show the quiz link

function showQuiz()

{
	    
	    var CeresVisited = sessionStorage.getItem( "Ceres" );

        var PallasVisited = sessionStorage.getItem( "Pallas" );

        var JunoVisited = sessionStorage.getItem( "Juno" );

        var VestaVisited = sessionStorage.getItem( "Vesta" );

        

        

        //alert( CeresVisited + ", " + PallasVisited + ", " + JunoVisited + ", " + VestaVisited );

        if(CeresVisited == "visited" && PallasVisited == "visited" && JunoVisited == "visited" && VestaVisited == "visited")

        {

                document.getElementById( "quiz-link" ).style.display = "inline";

        }

       

}



